Traditionally, a wide variety of illumination types has been used for internal spaces. Illumination is in that case traditionally used only if not enough daylight is available in the respective room. For example, illumination can be switched on using sensors as soon as the room that is to be illuminated becomes too dark, and the illumination can be switched off again as soon as it is light enough again. A room is illuminated here generally from the ceiling or from a side wall of the room. In other words, the artificial illumination originates from a different direction than the natural illumination. Natural illumination through a window or, for example, above doors or other construction elements can be realized using what is known as a transom light, also referred to as a transom window. A crossbeam (or another suitable support), which is also known as a transom, is generally located below the transom light.